Method of making wire-circuit sheet

ABSTRACT

A wire-circuit sheet comprising; a resin sheet with circuit connecting holes, wires lying across the circuit connecting holes, and a cutting holes to punch the resin sheet so as to cut simultaneously the wires. Further, a wire-circuit sheet and its manufacturing method comprising; a resin sheet on which a plurality of wires lie as crossing or coming close to each other, cutting holes being provided at the crossing or close points of the plurality of wires to cut off the wires and the sheet together, and the wires being fixed and sandwiched in between laminated resin sheets with a sticky surface. Moreover, in an electric junction box utilizing the wire-circuit sheet, a busbar-wire connecting method comprising the steps of: forming insertion holes through a cover in order to insert and fix busbar-tabs as terminals; inserting the busbar-tabs as terminals into the insertion holes in the cover; mounting a wire-circuit sheet at a predetermined position on the cover; and using the busbar-tabs as welding electrodes to weld the wires and the busbar-tabs together to connect them in a conductive state.

This is a division of application Ser. No. 08/377,231 Filed Jan. 24,1995.

BACKGROUND OF THE INVENTION

(1) Field of the Invention

The present invention relates to a wire-circuit sheet and an electricjunction box in which a plurality of the wire-circuit sheets arelaminated to form a high density circuit for a compact electric junctionbox.

(2) Description of the Prior Art

FIG. 23 shows a wire-circuit board of a conventional electric junctionbox disclosed in Japanese Utility Model Preliminary Publication No.64-9411.

This wire-circuit board assembly 30 is composed of a busbar-circuitboard 31 and a wire-circuit board 32. The busbar-circuit board 31 has aplurality of busbars 34 laid on an insulating resin substrate 33. Busbarterminal tabs 35 pierce the substrate 33 so as to extend downward from arear surface thereof. The wire-circuit board 32 has a plurality ofconductive wires 36, each end of which is connected by soldering witheach terminal piece 38 on an insulating substrate 37 so that each femaleterminal 39 associated with each terminal piece 38 can make contact witheach of the busbar terminal tabs 35.

However, the structure of the above mentioned conventional electricjunction box has a drawback that an electric junction box will becomebulky if the wire-circuit board assemblies 30 are multiply stacked toprovide an electric junction box having a high density circuit. Further,it requires a great deal of labor cost to connect the conductive wires36 by solder brazing to the wire-circuit board 32, which causes a lowproductivity rate. Moreover, residual wire chips may be undesirablyscattered in the electric junction box.

SUMMARY OF THE INVENTION

This invention has focused attention on the above drawback and aims toprovides a wire-circuit sheet being produced in an improved productivityand an electric junction box which is not bulky even when a plurality ofthe wire-circuit sheets are laminated therein to make a high densitycircuit.

(1) In one embodiment of the invention, to achieve the above mentionedobjects, a wire-circuit sheet comprises: a resin sheet with a circuitconnecting hole; a wire lying across the circuit connecting hole; and acutting hole to punch the resin sheet so as to cut simultaneously thewire. The wires are preferably sandwiched in between a couple of theresin sheets.

Further, an electric junction box in accordance with the presentinvention comprises: one or a plurality of resin sheets each of whichhas a circuit connecting hole; a wire lying across the circuitconnecting hole; and a cutting hole to punch each of the resin sheets soas to cut simultaneously the wire; an intermediate insulating boardinserted between the resin sheet to make the resin sheet folded to belaminated; a circuit board having a connecting portion with the resinsheet; and a case receiving the circuit board therein. The circuit boardpreferably has a protruding connection portion, wherein a throughopening is provided on an outer wiring resin sheet to communicate theconnecting portion with an inner wiring resin sheet.

Referring to the operation of the above mentioned invention, the wireson the wire-circuit sheet are exposed as crossing over the circuitconnecting holes to make contact with the circuit board or anotherwire-circuit sheet thereby. The wires are reliably positioned andsecured between the couple of the resin sheets. A plurality of circuitsare completed by the cutting holes to cut the wires. The intermediateinsulating board inserted between the resin sheet to make the resinsheet folded to be laminated. The outer wiring sheet lying on theintermediate insulating board makes contact directly with the circuitboard, while the inner wiring sheet makes contact with the connectionportions of the circuit board by the through openings.

(2) To achieve the above mentioned objects, a busbar-wire connectingmethod in regard to an electric junction box in accordance with thepresent invention comprises the steps of: forming a predetermined numberof circuit connecting holes through an insulating sheet; laying apredetermined number of wires on the insulating sheet in such a way asto cross the circuit connecting holes to form a wire-circuit sheet;forming insertion holes through a cover in order to insert and fixbusbar-tabs as terminals; inserting busbar-tabs as terminals intoinsertion holes in the cover; mounting the wire-circuit sheet at apredetermined position on the cover; and using the busbar-tabs aswelding electrodes to weld the wires and the busbar-tabs together toconnect them in a conductive state.

Referring to the operation of the invention set forth in the precedingparagraph, the wire-circuit sheet is fabricated in a separate assemblyline by laying wires between the insulating sheets in such a manner asto cross the circuit connecting holes piercing through the insulatingsheets. Then, in the main assembly line, the terminal busbar-tabs areinserted into the insertion holes in the cover and the wire-circuitsheet is aligningly positioned on the cover. The busbar-tabs are used aswelding electrodes to weld together the wires and the busbar-tabs in aconductive state. The wire laying process therefore can be separatedfrom the main assembly line. In the main assembly line the busbar-tabscan be positioned and held by the cover when they are being connected tothe wires. As a result, the wire-busbar connecting work becomes easy andthe time required for the connection is shortened. Because of thisconnection method, cut wire chips are not scattered on the main assemblyline, improving the productivity of the main assembly line.

A busbar-wire connecting apparatus in regard to an electric junction boxin accordance with the present invention, comprises: a wire-circuitsheet including an insulating sheet, a predetermined number of circuitconnecting holes piercing through the insulating sheet, and apredetermined number of wires laid on the insulating sheet in such a wayas to cross the circuit connecting holes; a cover having insertion holesformed therein; busbar-tabs as terminals inserted into the insertionholes in the cover; a jig having welding electrodes connected to thebusbar-tabs, the jig being adapted to hold the cover; and a weldingelectrode disposed on the wire-circuit sheet side.

Referring to the operation of the invention set forth in the predecingparagraph when the wires crossing the circuit connecting holes in thewire-circuit sheet are to be connected conductively to the busbar-tabsinserted into the insertion holes in the cover, the back of the cover issupported near the busbar-tabs by the jig so that the cover can resistthe pressing force of the welding electrode. Then, the welding electrodeis pressed against the wires crossing the circuit connecting holes andis applied electricity to weld the wires and busbar-tabs together. Inthe main assembly line, this connecting method can reduce the time ofand the efficiency of the wire-busbar connecting work.

A further busbar-wire connecting apparatus in regard to an electricjunction box in accordance with the present invention comprises: awire-circuit sheet including an insulating sheet, a predetermined numberof circuit connecting holes piercing through the insulating sheet and apredetermined number of wires laid on the insulating sheet in such a wayas to cross the circuit connecting holes; a cover having insertion holesformed therein; busbar-tabs as terminals inserted into the insertionholes in the cover; a busbar-tab positioning board which is providedseparately from the cover and has busbar-tab fixing holes for insertingto fix the busbar-tabs and welding holes, these holes piercing throughthe substrate; and, wherein after the busbar-tabs are fixed in thebusbar-tab fixing holes, the busbar-tabs and the wires are weldedtogether in a conductive state.

Referring to the operation of the invention set forth in claim 7, in aseparate assembly line, wires are laid between the insulating sheets insuch a way that the wires cross the circuit connecting holes in theinsulating sheets, thus forming the wire-circuit sheet. Then, thevertical portions of the terminal busbar-tabs are inserted into thebusbar-tab fixing holes in the busbar-tab positioning board. Thewire-circuit sheet is aligningly positioned on the busbar-tabpositioning board. After this, in the main assembly line, thewire-circuit sheet together with the busbar-tab positioning board ismounted on the cover to insert the vertical portions of the busbar-tabsinto the insertion holes in the cover. At the same time, the wirescrossing the circuit connecting holes in the wire-circuit sheet areconductively welded to the busbar-tabs fixed in the cover through thewelding holes formed in the busbar-tab positioning board. With thisconnecting method, because the wire laying process can be separated fromthe main assembly line, the wire-busbar connecting time in the mainassembly line can be reduced. Further, because residual wire chips arenot scattered in the main assembly line, the productivity of the mainline can be improved.

A further busbar-wire connecting method set forth in regard to anelectric junction box in accordance with the present invention comprisesthe steps of: forming a predetermined number of circuit connecting holesthrough an insulating sheet; laying a predetermined number of wires onthe insulating sheet in such a way as to cross the circuit connectingholes to form a wire-circuit sheet; forming insertion holes through acover for inserting and fixing of busbar-tabs as terminals; using abusbar-tab positioning board provided separately from the cover to fixthe busbar-tabs, the busbar-tab positioning board having busbar-tabfixing holes and welding holes, these holes piercing through the board;positioning the wire-circuit sheet with respect to the busbar-tabpositioning board; welding together the busbar-tabs and the wires byusing the welding holes; and stacking the busbar-tab positioning boardon the cover in such a way that the busbar-tabs are inserted into theinsertion holes in the cover.

Referring to the operation of the invention set forth in the precedingparagraph, in the separate assembly line, wires are laid on theinsulating sheet in such a way as to cross the circuit connecting holesin the insulating sheet to form the wire-circuit sheet. Then, thevertical portions of the terminal busbar-tabs are inserted into thebusbar-tab fixing holes in the busbar-tab positioning board so that theyare firmly positioned and fixed. The wire-circuit sheet is aligninglystacked on the busbar-tab positioning board. The wires crossing thecircuit connecting holes in the wire-circuit sheet are conductivelywelded through the welding holes to the busbar-tabs fixed in thebusbar-tab positioning board. Then, in the main assembly line, thewire-circuit sheet together with the busbar-tab positioning board ismounted on the cover to insert the vertical portions of the busbar-tabsinto the insertion holes in the cover. With this connecting method, thewire laying process can be separated from the main assembly line.Further, the connection between the wires and the busbar-tabs can beperformed in the separate assembly line with the busbar-tabs firmlypositioned by the busbar-tab positioning board. The connection worktherefore can be done easily. Further, because residual wire chips arenot scattered in the main assembly line, the productivity of the mainassembly line can be improved.

A further busbar-wire connecting method in regard to an electricjunction box in accordance with the present invention is a methodaccording to the second preceding paragraph, which further comprises thesteps of: forming protrusions on the cover that fit into the weldingholes in the busbar-tab positioning board; and filling the welding holesby the protrusions when the busbar-tab positioning and welding board isstacked on the cover.

Referring to a further operation of the invention the cover is providedwith protrusions that fit into the welding holes in the busbar-tabpositioning board, when the busbar-tab positioning board is stacked onthe cover, such that the welding holes are filled by the protrusions.This prevents water from collecting in and seeping through the weldingholes in the busbar-tab positioning board, so that the connectedbusbar-tabs and wires can be protected.

(3) In accordance with further aspects of the present invention, toachieve the above mentioned objects, a wire-circuit sheet of thisinvention comprises: a resin sheet on which a plurality of wires lie ascrossing or coming close to each other; cutting holes provided at thecrossing or close points of the plurality of wires to cut the wires andthe sheet together; and the wires being fixed and sandwiched in betweenthe laminated resin sheets with a sticky surface.

And, a manufacturing method for a wire-circuit sheet of this inventioncomprises the steps of: a plurality of wiring pins are slidably insertedin holes formed on a wire-laying base plate; the plurality of pins areprojected on the wire-laying base plate and are resiliently supported bysprings; wires are laid between the pins by a wire positioning feeder;an upper adhesive resin sheet is provided and pressed to the wires laidon the base plate to bond thereto; a lower resin sheet is provided andpressed to the upper resin sheet with the bonded wires; thus wires arebonded to be fixed between the upper and lower resin sheets; and cuttingholes are provided at crossing or close points of the plurality of wiresto cut the wires and the sheet together. Positioning holes arepreferably formed in the upper and lower resin sheets with wires beingfixed therebetween. The resin sheet can be fed from a rolled sheet orcan be handled as piece substrates by a carrier with a suction cap.

The upper resin sheet is pressed to the wire-laying base plate, whichmakes the pins retracted, and the wires are bonded to the upper resinsheet. Then, the lower resin sheet is bonded to the upper resin sheetwith the wires therebetween so that the wires can stick to both of theupper and lower sheets to be fixed without any deviation. Further, thepositioning holes in the resin sheets are advantageous for correctlypositioning the wire-circuit sheet in an electric junction box or thelike. Moreover, cutting holes piercing through the resin sheet areprovided at crossing or close points of the plurality of wires so as tocut off the wires to make a plurality of separate circuits.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is an exploded perspective view showing an embodiment of anelectric junction box utilizing wire-circuit sheets according to thisinvention;

FIG. 2 is a perspective view, partially broken away, showing a part ofthe embodiment in FIG. 1;

FIG. 3 is a top view showing an outer wire-circuit sheet according tothis invention;

FIG. 4 is a top view showing an inner wire-circuit sheet according tothis invention;

FIGS. 5A to 5C are top views showing manufacturing processes ofwire-circuit sheets according to this invention;

FIG. 6 is a longitudinal sectional view of an electric junction boxaccording to this invention;

FIG. 7 is a perspective view showing an aspect of the connection inregard to connector terminals in FIG. 6; and

FIG. 8 is a perspective view showing busbar-tabs before being insertedand fixed in tab insertion holes in the cover of the electric junctionbox;

FIG. 9 is a perspective view showing the cover of the electric junctionbox attached with the busbar-tabs which is aligned with the wire-circuitsheet and jig;

FIG. 10 is a partial side cross section showing the busbar-tabsconnected to the wire of the wire-circuit sheet;

FIG. 11 is a perspective view showing a part of the completedwire-circuit sheet;

FIG. 12 is a perspective view showing busbar-tabs and a part of abusbar-tab positioning board;

FIG. 13 is a perspective view showing a wire and the busbar-tabs beforebeing connected;

FIG. 14 is a perspective view showing the wire and the busbar-tabsaligned and connected;

FIG. 15 is a partial side cross section showing the wire and thebusbar-tab being connected by a welding horn;

FIG. 16 is a perspective view showing the busbar-tab positioning boardwith their wire and busbar-tabs connected, and also the cover of theelectric junction box;

FIG. 17 is a partial side cross section showing the wire and thebusbar-tab that, after having been connected together, are mounted onthe cover of the electric junction box;

FIG. 18 is a perspective view of an embodiment of a manufacturing methodin regard to a wire-circuit sheet according to this invention;

FIG. 19 is a perspective view of a wire-circuit sheet according to thisinvention;

FIG. 20 is a perspective view showing a method for handling andsupplying resin sheets by a handling arm with a suction cap according tothis invention;

FIGS. 21A & 21B are perspective views showing a method for formingcutting holes at crossing parts of wires according to this invention;

FIGS. 22A & 22B are perspective views showing a method for formingcutting holes at close parts of wires according to this invention; and

FIG. 23 is an exploded perspective view showing a conventional circuitboard utilizing in an electric junction box.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT

FIGS. 1 and 2 show an embodiment of an electric junction box utilizingwire-circuit sheets in regard to this invention.

The electric junction box 1 comprises: a couple of wire-circuit sheets 2and 3; an intermediate insulating board 4 inserted between the couple ofwire-circuit sheets 2,3 to make the wire-circuit sheets folded at themiddle portion thereof and laminated; busbar-circuit boards 7,8 havingconnection portions 5₁,5₂, 6 corresponding to the wire-circuit sheets2,3; and, an upper and lower covers 9,10 receiving the busbar-circuitboards 7,8.

The wire-circuit sheets 2,3 have conductive open-wires 12 laid onflexible resin sheets 11. Through connection holes 13 formed in advanceon the resin sheets, the wires 12 are connected to the wires 12 on theother resin sheet or the connection portions 5₁,5₂, 6 of thebusbar-circuit boards 7,8. Further, predetermined portions of the wireshave being cut by cutting holes 14 in regard to each sheet 11respectively. The number of wire-circuit sheets is not limited to twoand may be one or more than two. The busbar-circuit boards 7,8 may bealtered to print circuit boards or any other circuit boards.

In FIG. 1, the wire-circuit sheet 3 opposing to the busbar-circuitboards 7,8 has the through openings 15₁, 15₂ corresponding to theconnection portions 5₁,5₂ of the bus bar-circuit boards 7,8, so that thewire-circuit sheet 2 opposing to the insulating board 4 can make contactdirectly with the connection portions 5₁,5₂. The connection portions5₁,5₂ is composed of terminal ends 17 of projecting bars 16 on thesurface of the busbar-circuit boards 7,8 received in the covers 9,10.

The connection portions 6 of lower busbars of the circuit boards 7,8connect with the wire-circuit sheet 3. The terminal ends 17 of theprojecting bars 16 connect with the wire-circuit sheet 2. The wires 12on each of wire-circuit sheets 2,3 connect with the wires 12 on eachother sheet through the circuit connecting holes 13. Coated wires may beutilized in stead of open-wire 12, wherein wires can lie across eachother on the resin sheet 11, but the wires positioned at the circuitconnecting holes 13 are required to be stripped the insulating coat off.

The couple of wire-circuit sheets 2,3, as shown in FIG. 2, are folded atthe middle portion thereof and laminated with an intermediate insulatingboard 4 inserted into them. The couple of folded wire-circuit sheets 2,3are received between the upper and lower covers 9,10. The upper cover 9combines with the lower cover 10 by engaging a locking claw 19 thereofwith a protrusion 18 formed on the lower cover 10. The couple of upperand lower covers may be combined to be opened and closed by a hingeconnection(not shown). One end of the intermediate insulating board 4 isformed as a thickness-reduced plate 20 so that an end part 2a,3a can befurther folded to be laminated. As a result, the couple of wire-circuitsheets 2,3 can be positioned in the both stepped space 21,22 opposing tothe thickness-reduced plate 20.

FIGS. 3,4 shows an example of the outer wire-circuit sheet 3 and theinner wire-circuit sheet 2 respectively. The resin sheet 11 of the outerwire-circuit sheet has a plurality of through holes 15 and,corresponding to the through holes 15₃ to 15₇, circuit connecting holes13₃ to 13₇ are provided and positioned in the inner wire-circuit sheet2. At each of the circuit connecting holes 13, conductive open-wires 12are positioned, while cutting holes 14 are appropriately arranged tomake separate circuits.

FIGS. 5A, 5B and 5C show manufacturing processes for the wire-circuitsheet 2. One wire-circuit sheet 2 comprises, as shown in FIG. 5A, acouple of insulating resin sheets 11/11 being the same in size. Each ofthe resin sheets 11 has circuit connecting holes 13 arranged in advanceat the same positions as each other. One of the resin sheets 11, asshown in FIG. 5B, is bonded to the other resin sheet 11 after theconductive wire 12 is laid on the one of the resin sheets 11. The wire12 is laid across the circuit connecting holes 13.

The wire 12 is initially laid on a pin board for wiring by a wirehandling arm head(not shown) and then shifted to the resin sheet 11 soas to be laid thereon. The resin sheet 11 is made of saturated polyesterresin or the like. On the surface of the resin sheet 11, a thermoplasticadhesive (a hot-melt adhesive or the like) is coated. The wire 12 isbonded and fixed on the resin sheet 11 by a hot-press. Finally, as shownin FIG. 5C, the cutting holes 14 are formed at predetermined positionsto cut the wire 12 for every sheet 11 and to complete each wire-circuitsheet 2. The wire-circuit sheet 2 is produced in a process differed froman assembling line of the electric junction box 1.

FIG. 6 shows a longitudinal cross sectional view of the above mentionedelectric junction box 1. At one end of intermediate insulating board 4,the couple of wire-circuit sheets 2,3 are folded. While, on athickness-reduced plate 20 formed at the other end, end parts 2a,3a ofwire-circuit sheets 2,3 are further folded to be laminated. The coupleof wire-circuit sheets 2,3 are combined to each other by pins 23. In thethrough openings 15 of outer wire-circuit sheet 3, a connectionterminals (busbar terminals) 24 are provided to connect with the innerwire-circuit sheet 2. While, the outer wire-circuit sheet 3 connectsdirectly with connection terminals (busbar terminals) 25.

FIG. 7 shows an aspect of the connection in respect of the connectionterminals 24,25 which are completely connected to the wires 12 on thewire-circuit sheets 2,3 by heated depositions 26 due to soldering, beamwelding or suchlike.

In this embodiment, open-wires are applied for the wire 12 and the openwires are caught and fixed between a couple of the resin sheets 11. Whencoated wires are utilized, only one resin sheet 11 is required to forman insulating wiring sheet, which reduces an assembly work. In thiscase, the couple of resin sheets 11 may be naturally utilized to havethe advantage that the wires 12 do not come off easily and are reliablypositioned.

As mentioned above, this embodiment provides the electric junction boxwith high density and compact circuits as the plurality of flexiblewire-circuit sheets are laminated to compose the junction box. Besides,the wire-circuit sheets are produced in a process differed from aproduction line of the electric junction boxes, which achieves a simplerproduction line of the electric junction boxes and reduces the cost ofequipment. Further, the equipment for wiring of wire-circuit sheets canbe commonly used to increase productivity. Moreover, residual wire chipsmay not be undesirably included in the electric junction box.

FIG. 7 is also showing, as one embodiment, a method of connecting wiresand busbar-tabs in regard to an electric junction box. When, forexample, a busbar-tab 24a is connected to a wire 12a on the wire-circuitsheet 3, a wire part crossing the circuit cutting hole 14 is firstlyformed as it is predetermined and then the busbar-tab 24a is broughtinto contact with the lower insulating sheet at the circuit connectinghole 26a. Then, a first welding horn (welding electrode), not shown, isput in contact with a part of the wire 12a crossing the circuitconnecting hole 26a from the upper insulating sheet side and a secondwelding horn, not shown, is also placed in contact with the back of thebusbar-tab 24a. In this condition, electricity is applied. This causesthe part of the wire 12a crossing the circuit connecting hole 26a andthe busbar-tab 24a to be connected. This method is similarly performedto connect a part of wire 12b crossing another circuit connecting hole26b and a busbar-tab 24b and to connect a part of wire 12 crossing stillanother circuit connecting hole 26c and a busbar-tab 25.

After the wires 12a, 12b, 12 are connected to the busbar-tabs 24a, 24b,25, the vertical portions of the busbar-tabs 24a, 24b, 25 are insertedinto the tab insertion holes (not shown) in the lower cover 10 and fixedthere. This enables the wire-circuit sheet 3 to be mounted on the uppercover 9 and the lower cover 10.

The similar process is performed in connecting a bus bar-tab to a wire12 in the wire-circuit sheet 2. This process involves mounting thewire-circuit sheet 2 on the wire-circuit sheet 3; putting the busbar-tabinto contact with the lower insulating sheet at an area corresponding tothe circuit connecting hole 13, which is crossed by the wire 12; puttinga first welding horn not shown in contact with the part of the wire 12crossing the circuit connecting hole 13, from the upper insulating sheetside of the wire-circuit sheet 2; putting a second welding horn notshown in contact with the back of the busbar-tab; and applyingelectricity. With these steps taken, the wire 12 crossing the circuitconnecting hole 13 can be connected with the busbar-tab. This busbar-tabis inserted into a tab insertion hole in the lower cover 10, along withthe busbar-tabs 24a, 24b, 25 connected to the wires 12a, 12b, 12 of thewire-circuit sheet 3.

Next, by referring to FIGS. 8 to 10, another embodiment of thewire-busbar connecting method in regard to an electric junction box isexplained. FIG. 8 is a perspective view showing the busbar-tabs beforebeing inserted into the tab insertion holes in the cover of the electricjunction box. FIG. 9 is a perspective view showing the cover of theelectric junction box attached with the busbar-tabs which is alignedwith the wire-circuit sheet and a jig. FIG. 10 is a partial side crosssection showing the busbar-tabs connected to the wire of thewire-circuit sheet.

Firstly, as shown in FIG. 8, in a wire-circuit sheet 81, a wire 87 islaid to cross circuit connecting holes 83a, 83b and a circuit cuttinghole 85. A part of the wire 87 crossing the circuit cutting hole 85 iscut to complete a wire-circuit sheet 81.

Secondly, busbar-tabs 100a, 100b are brought to tab insertion holes123a, 123b in the cover 121 of the electric junction box. With thevertical portions of the busbar-tabs 100a, 100b inserted and fixed inthe tab insertion holes 123a, 123b of the cover 121, the wire-circuitsheet 81 is placed on the cover 121 and a welding horn 111 is positioneddirectly above the circuit connecting hole 83a of the wire circuit sheet81. At the same time, the jig 131 is located immediately below theposition where the busbar-tabs 100a, 100b are inserted and fixed in thecover 121.

The jig 131, as shown in FIG. 10, has a retainer portion 133 thatengages the back of a surface plate 125 of the cover 121 on which thebusbar-tabs 100a, 100b are mounted. This retainer portion 133 supportsthe surface plate 125 when the welding horn 111 is pressed against thewires 87a, 87b through the circuit connecting holes 83a, 83b in thewire-circuit sheet 81 placed on the cover 121. The jig 131 has on bothsides of the retainer portion 133 electrode portions 135a, 135b that fitover the vertical portions of the busbar-tabs 100a, 100b inserted andfixed in the tab insertion holes 123a, 123b of the cover 121. Theelectrode portions 135a, 135b are each U-shaped in side view andelastically clamp the vertical portions of the busbar-tabs 100a, 100b.The electrode portions are protected around their circumference byprotective plates 137a, 137b and are connected with wires 139a, 139bleading to a power supply not shown.

With the welding horn 111 positioned directly above the circuitconnecting hole 83a of the wire-circuit sheet 81 mounted on the cover121 and with the jig 131 situated immediately beneath the position wherethe busbar-tabs 100a, 100b are inserted and fixed in the cover 121, theretainer portion 133 is engaged with the back of the surface plate 125where the busbar-tabs 100a, 100b are situated in the cover 121. At thesame time, the electrode portions 135a, 135b of the jig 131 are fittedover the vertical portions of the busbar-tabs 100a, 100b inserted andfixed in the tab insertion holes 123a, 123b of the cover 121.

Next, the welding horn 111 is lowered to contact the wire 87a thatcrosses the circuit connecting hole 83a in the wire-circuit sheet 81 andcurrent is applied to the welding horn 111 and the electrode portions135a, 135b of the jig 131 to fix the wire 87a and the busbar-tab 100atogether. With the wire 87a and the busbar-tab 100a welded together, thewelding horn 111 is returned to the home position and at the same timethe cover 121 of the electric junction box is shifted for the nextwelding of the busbar-tab 100b and the wire 87b crossing the circuitconnecting hole 83b in the wire-circuit sheet 81. After the wires 87a,87b and the busbar-tabs 100a, 100b are welded together, the welding horn111 is again returned to its home position and the retainer portion 133of the jig 131 is parted from the back of the surface plate 125 of thecover 121. Then electrode portions 135a, 135b of the jig 131 are removedfrom the vertical portions of the busbar-tabs 100a, 100b.

Because this embodiment uses the jig 131 having the retainer portion 133for supporting the back of the surface plate 125 of the cover 121 andthe electrode portions 135a, 135b for applying electricity to thevertical portions of the busbar-tabs 100a, 100b secured to the cover121, it is possible to securely position the busbar-tabs 100a, 100b byinserting them into the cover 121 of the electric junction box and tofixedly connect the wires 87a, 87b of the wire-circuit sheet 81 and thebusbar-tabs 100a, 100b. This shortens the time taken to connect thewires 87a, 87b of the wire-circuit sheet 81 and the busbar-tabs 100a,100b and also improves the workability.

Further, this method obviates a jig that would otherwise be required forfixing the busbar-tabs when connecting the wires 87a, 87b and thebusbar-tabs 100a, 100b. The process of transferring the busbar-tabs fromthe fixing jig also becomes unnecessary, reducing the facility cost andthe number of processes.

Next, by referring to FIGS. 11 to 17, a still another embodiment of thewire-busbar connection method is described. FIG. 11 is a perspectiveview showing a part of the completed wire-circuit sheet. FIG. 12 is aperspective view showing busbar-tabs and a part of a busbar-tabpositioning board. FIG. 13 is a perspective view showing a wire and thebusbar-tabs before being connected. FIG. 14 is a perspective viewshowing the wire and the busbar-tabs aligned and connected. FIG. 15 is apartial side cross section showing the wire and the busbar-tab beingconnected by a welding horn. FIG. 16 is a perspective view showing thebusbar-tab positioning board with their wire and busbar-tabs connected,and also the cover of the electric junction box. FIG. 17 is a partialside cross section showing the wire and the busbar-tab that, afterhaving been connected together, are mounted on the cover of the electricjunction box.

Firstly, as shown in FIG. 11, the wire 87 is laid in the wire-circuitsheet 81 in such a way as to cross the circuit connecting holes 83a, 83band the circuit cutting hole 85. A part of the wire 87 crossing thecircuit cutting hole 85 is cut off to complete the wire-circuit sheet81.

Secondly, as shown in FIG. 12, a busbar-tab positioning board 151 isformed. The busbar-tab positioning board 151 is made from an insulatingthin plate, which, at predetermined positions corresponding to thepositions where the tab insertion holes are formed in the cover of theelectric junction box, is formed with busbar-tab fixing holes 153a, 153binto which the vertical portions of the busbar-tabs 100 are inserted andfixed at predetermined positions. The busbar-tab fixing hole 153a is ahole for the busbar-tab 100a that connects to that portion of the wire87a which crosses the circuit connecting hole 83a of the wire-circuitsheet 81; and the busbar-tab fixing hole 153b is a hole for thebusbar-tab 100b that connects to that portion of the wire 87b whichcrosses the circuit connecting hole 83b of the wire-circuit sheet 81.

Between the busbar-tab fixing holes 153a, 153b, the busbar-tabpositioning board 151 has welding holes 155a, 155b formed therein topass the first welding horn 111 described later, at positionscorresponding to the position where the circuit connecting holes 83a,83b are formed in the wire-circuit sheet 81.

The welding holes 155a, 155b, which are formed between the busbar-tabfixing holes 153a, 153b in this embodiment, have their positionsdetermined according to the condition of laying the wires 87a, 87b andto the direction of busbar-tabs 100a, 100b inserted in the cover of theelectric junction box and therefore can be arbitrary changed accordingto the design specification.

Then, as shown in FIG. 13, the vertical portions of the busbar-tabs100a, 100b are inserted into the busbar-tab fixing holes 153a, 153b inthe busbar-tab positioning board 151 so that they are fixed atpredetermined positions. Then, as shown in FIG. 14, the wire-circuitsheet 81 is mounted on the busbar-tabs 100a, 100b which were positionedon the busbar-tab positioning board 151 in such a way that thoseportions of the wires 87a, 87b that cross the circuit connecting holes83a, 83b of the wire-circuit sheet 81 are placed on the respectivebusbar-tabs 100a, 100b.

This is followed by the step shown in FIG. 15. The first welding horn111 is lowered from the outside of the upper insulating sheet of thewire-circuit sheet 81 to contact the wire 87b crossing the circuitconnecting hole 83b. The second welding horn 113 is raised into thewelding hole 155b of the busbar-tab positioning board 151 at the back ofthe busbar-tab 100b until it contacts the busbar-tab 100b. Then, thefirst and second welding horns 111, 113 are energized to connect thewire 87b crossing the circuit connecting hole 83b and the busbar-tab100b. After this, the first and second welding horns 111, 113 arereturned to their home positions. This process is also performed to thewire 87a that crosses the circuit connecting hole 83a.

Then, as shown in FIG. 16, the wire-circuit sheet 81 and the busbar-tabpositioning board 151 that are combined by connecting the wires 87a, 87band the busbar-tabs 100a, 100b are mounted on the cover 165 of theelectric junction box. On the surface of the cover 165 (where thebusbar-tab positioning board 151 is mounted) at specified positions,i.e., at positions corresponding to the circuit connecting holes 83a,83b of the wire-circuit sheet 81, are formed protrusions 167a, 167b thatare inserted into the welding holes 155a, 155b in the busbar-tabpositioning board 151. Thus, when the integrated wire-circuit sheet 81and busbar-tab positioning board 151 are mounted on the cover 165 of theelectric junction box, the protrusions 167a, 167b of the cover 165 fitinto the welding holes 155a, 155b, thus preventing water from beingcollecting in and seeping through the welding holes 155a, 155b in thebusbar-tab positioning board 151.

Because this embodiment employs the busbar-tab positioning board 151 forpositioning the busbar-tabs 100a, 100b that connect to the wires 87a,87b crossing the circuit connecting holes 83a, 83b in the wire-circuitsheet 81, when the busbar-tabs 100a, 100b connected to the wires 87a,87b are inserted into the tab insertion holes in the cover 165, they canbe prevented from being deviated and be securely inserted and fixed.Therefore, the time required for the insertion into the tab insertionhole in the cover 165 can be reduced, improving the workability.

Further, the busbar-tab positioning board 151 works as a jig during thewelding process, thereby eliminating the need for dedicated jigs andpreventing an increase in the facility cost.

FIG. 18 shows an embodiment of a manufacturing method in regard towire-circuit sheets according to this invention.

The wire-circuit sheet 201, as shown in FIG. 19, is composed of a coupleof upper and lower insulating resin sheets 202,203 in which coated wires204 are fixed by bonding therebetween. The one side surfaces of theinsulating resin sheets 202,203 are coated by a thermoplastic adhesive.

In FIG. 18, the upper insulating resin sheet 202 is fed from a rolledsheet 207, via a guiding roller 208, to come under a heating unit 209.The heating unit 209 is actuated vertically by an air cylinder 210.Below the upper insulating resin sheet 202 positioned under the heatingunit 209, a conventional wire-laying board 211 is transferred by alaterally extending screw shaft 212. On the wire-laying board 211, thecoated wires 204 are laid so as to complete a predetermined circuit. Thewires 204 are laid by a wire handling arm head 214 as well as aconventional method, whereby the wire-laying board 211 is shifted byscrew shafts 212, 213 extending toward X or Y direction.

On the board 211 which is transferred under the upper insulating resinsheet 202, the heating unit 209 comes down by the air cylinder 210. Theheating unit 209 presses and moves back wiring pins on the board 211with a base plate 216 so that the wire 204 is bonded on the lowersurface of the upper resin sheet 202. That is, the heating unit 209makes the upper resin sheet 202 soft and melts the thermoplasticadhesive so that the wire 204 can be bonded on the upper resin sheet 202as maintaining the wiring pattern arranged on the wire-laying board 211.

Then, at the stage a little proceeding along the sheet delivery line (ina direction shown by an arrow), a lower resin sheet 203 is provided froma sheet roll 217. On the upper surface of the lower resin sheet 203, thethermoplastic adhesive is coated also. A heating unit 218 similar to theaforementioned one is equipped as opposing to and positioned under thelower resin sheet 203. A pressing plate 219 is arranged, as opposing tothe heating unit 218, above the upper resin sheet 202. The heating unit218 lifted by the air cylinder 220 presses the lower resin sheet 203 tobond to the upper resin sheet 202. The resin sheet 202, 203 become softby the heating unit 218 so as to make close contact with the wire 204,and the wire 204 is firmly bonded to fix between both of the resin sheet202,203 without any deviation.

After the wire is bonded, both of the resin sheet 202, 203 are providedwith positioning through-holes 221 situated at their four corners(whichwill be cut off when the resin sheet 202, 203 are completed). Thepositioning holes 221 are used, for example, for positioning to set thewire-circuit sheet in a conventional junction box housing. Thepositioning holes 221 are formed, for example, by punching pins 222provided on the four corners of the heating unit 218 at the same time asthe bonding of both of the resin sheets 202, 203. After bonded andpunched to make the holes, the resin sheet 202, 203 are cut finally in apredetermined length to be completed as a wire-circuit sheet 201 such asshown in FIG. 19.

While, as shown in FIG. 20, the resin sheet may be transferred, as aprecut rectangular resin sheet 224, directly on the wire-laying board211 by using a handling arm with a vacuum suction cap 223 instead ofsupplying by sheet rolls 207, 217. In this case, the upper resin sheetsubstrate 224 having the wire 204 bonded thereon by the heating unit 218is stuck by the suction cap 223 and moved by the handling arm. A lowerresin sheet substrate(not shown) is similarly set up on another heatingunit(numeral 218 in FIG. 18) by using another suction cap assembly.

Further, on the wire-circuit sheet 201, the wires 204, as shown in FIG.21A, are crossed over each other or are, as shown in FIG. 22A, laidclose to each other. The crossing parts 225 and close parts 226 of thewires 204, as shown in FIG. 21B or FIG. 22B, are cut off by wire cuttingholes 227 so as to obtain separated wire circuits. While, on the resinsheets 202, 203, circuit connecting holes 228 are provided in advance atconnection parts with pressed contact terminals in an electric junctionbox, and the wires 204 are bonded on the sheets to be positioned justabove the circuit connecting hole 228.

As the wire cutting holes 227 are provided at the crossing parts 225 andclose parts 226 of the wires 204 so that a couple of wires can be cutoff together at once, approximately one half of man-hours for punchingholes are saved, and the number of the cutting holes are reduced so thatwiring spaces for the wires 204 on the wire-circuit sheet 201 can bebroader.

Thus, according to this invention, the wires are fixed between thecouple of resin sheets as keeping the wiring pattern set up on thewire-laying base plate. Therefore, the wire-circuit sheet, for example,can be connected to pressed contact terminals in an electric junctionbox in another production line so that a production line for multi-kindsof products, each of which is not so many, can be achieved in stead of aconventional one-pass production line with an expensive equipment cost.Besides, the wire-circuit sheets are surely set in an electric junctionbox by the positioning holes of the wire-circuit sheets so that the wirecan be positioned correctly for the pressed terminals of the electricjunction box.

Further, as the wire cutting holes are formed in the manufacturing stageof wire-circuit sheets, cutting residuals of wires can not enter intothe electrical junction box. And, as the wire cutting holes are providedat the crossing parts and close parts of the wires, it omits aconventional work of cutting wires by using an ordinary cutter andimproves the productivity. That is, one half of man-hours for punchingholes are saved in comparison with a work process that only one of thewires is cut at once. Therefore, the punching work to provide cuttingholes becomes more effective and wiring spaces for the wires on thewiring sheet can be broader so that more wire circuits can be providedon the wiring sheet.

What is claimed is:
 1. A method of manufacturing a wire-circuit sheetcomprising the steps of: slidably inserting a plurality of wiring pinsinto holes formed on a wire-laying base plate, said plurality of pinsbeing resiliently by springs which bias said pins to a position wheresaid pins extend from a surface of said base plate; laying wires betweensaid pins by a wire positioning feeder; pressing a first resin sheethaving adhesive on a surface of said first resin sheet to said wireslaid on said base plate to bond said first resin sheet to said wires;and pressing a second resin sheet having adhesive on a surface of saidsecond resin sheet to said first resin sheet with said bonded wires, sothat said wires are bonded between said first and second resin sheets.2. A manufacturing method for a wire-circuit sheet as claimed in claim1, wherein said first and second resin sheets are continuously suppliedfrom rolled sheets.
 3. A manufacturing method for a wire-circuit sheetas claimed in claim 1, wherein said first and second resin sheets aresupplied as each piece of resin sheets by handling arms with a vacuumsuction cap.
 4. A manufacturing method for a wire-circuit sheet asclaimed in claim 1, further comprising forming positioning holes in saidfirst and second resin sheets with said wires being fixed therebetween.5. A manufacturing method for a wire-circuit sheet as claimed in claim1, further comprising forming cutting holes in at least one positionwhere a plurality of wires lie sufficiently close to each other thatsaid wires and said sheets are cut off together.